At least four people were killed and nine others were injured in a shooting incident in a nightclub in the US city of Birmingham on Saturday, police said.

Investigators believe at least one person fired shots from the street into the nightclub on 27th Street North, where responding officers found multiple gunshot victims around 11 p.m. local time, Birmingham Officer Truman Fitzgerald said in a video statement as quoted by CNN.

Two women inside the nightclub and a man who was found on a sidewalk near the venue were pronounced dead at the scene, police told the news channel.

According to reports, another person died at hospital.

Multiple gunshot victims later arrived at a hospital, and there were are at least nine people still receiving treatment early Sunday, police said.

No arrests have been made so far,

Police have not identified any suspect so far.

The motive behind the shooting is still not clear.

“Detectives are working to determine what led to shots being fired and the victims being shot,” Fitzgerald told CNN.